How long and how strong must a climatic anomaly be in order to evoke a social transformation? Historical and contemporaneous case studies

In recent years, scholarly interest in the nexus between climate change and human societies has risen dramatically. This article asks: what type of climatic anomalies can undermine social stability, and what duration and intensity are necessary to instigate structural change? Contrary to a focus on short, dramatic events (storms, mudslides), the authors argue that gradual and more "usual" anomalies—prolonged droughts, cold spells, or untimely rains—have deeper, long-term impacts by reducing food availability. Based on qualitative examinations of collapse periods in western Asia and northern China (11th–early 12th centuries) and a high-resolution re-examination of Mali’s 2010s crisis, they contend that extended anomalies affecting food supply accelerate decisive processes, spur migration, increase violence and religious extremism, and lead to structural societal changes.

Tal Ulus, Ronnie Ellenblum